Individual Differences in Size and Shape & What It Means for Individual Running Mechanics
Midway through a group hill workout in DC during winter 2015, we were greeted by a woman walking her uber-fit looking dog who also had a ton of energy. I’m ones of those people who habitually pets dogs on the street, so I took an extra 10-second recovery before the next rep to say hello to the dog (and the owner, of course :) She said, "Oh, I bet he could keep up with you going up that hill." My initial inner-thought was, "I bet you dollars to gel packs that this dog would not only keep up, but this dog would smoke us up that hill and never be seen again." I had that thought because I noticed this dog looked like a running machine! The springy legs, the overall muscle, and even its eye-of-the-tiger. Body type certainly has an effect on capabilities, mechanics, and performance. And away we go!
A common goal for many athletes during their winter off-season is to reshape their bodies in terms of lean tissue vs. fatty tissue (i.e., body composition). This doesn't mean we have to be vain, yet we (myself included) simply recognize where some changes can be made, right? Solid side note: Although “looking good” seems like a great motivator for some people to begin a workout regiment (especially with NYE Resolutions…insert high-five emoji here ___), unfortunately the social psych research shows this is one of the least motivating reasons for exercise/training, and the drop-out rates are highest amongst those who list “lose weight/ look good” as their primary (key word) reason for working out/ exercise. In other words, they have long abandoned their gym membership by the time June rolls around. There’s a confluence of factors here (another time), so I’ll move on…
It is far more important to maintain a perspective to “transform your body so that you perform well.” In turn, running faster and/or farther will then be easier. You'll feel like an athlete and that's a wonderful feeling. Having athletic goals (versus aesthetic goals) will do much more for your self-esteem over the long haul (harkening the pathology of eating disorders and the mental corrections therein). As a result, you’re more likely to end up with enhanced confidence in your abilities and pleased with any physiological changes you can visibly see.
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Going back to that doggo on the hills, we do breed some types of dogs and horses to be faster and stronger for purposes of speed/endurance performance and Vegas gambling odds. We have the capacity to be very direct and selective with animals, yet not so much with humans. The now defunct ESPN Magazine used to publish its "Body Type" issue each year, where athletes representing the full spectrum of different sports posed in their skimmies. With a strong dose of photo shopping/editing, you get to see what the body types look like across various sports. Some body types are more advantageous for basketball, some are better for discus throwing, and others are better suited to sprint up a hill like a wild dog. And even within the different sports, some body types are better matched with certain positions/events, like a scrum-half in rugby or wide receiver in football. My initial deep-dive on this topic in 2015 came on the heels of finishing a marvelously written book called The Sports Gene by David Epstein, who was a pretty good collegiate runner himself. This book is now in my top-10 books of all time, which is a damn tough honor to achieve.
Epstein’s book highlights how our loooong genetic evolution has made certain populations of humans (based on ethnicity, regional diet, and regional weather) primed for certain athletic pursuits. Nature vs. Nurture? It's always both, but this book delves deeper into the details of the who, what, when, where, why and how of elite performance from the point of view of genetics, muscle fiber types, height, leg length, ankle mass, and you name it. Epstein is an outstanding writer. He presents clarity in his points, he's very clever and witty, and extremely on-point with a scientific mind that helps dispel many myths we once held about elite performance (i.e., “the 10,000-hours rule or the 10-year rule”). He even covers the game of chess in chapter 1 while he explains the vision/eyesight of elite athletes and why/how it's different than the general population. Even if you have no interest in reading “a book about sports," so be it, you can believe that this book often merely uses sports as a backdrop. In other words, if you're like me and you enjoy reading about evolutionary biology, evolutionary psychology, anthropology, and history, then give it a whirl!
To come back to the main point, without becoming obsessed with your body, continue to brainstorm and be brutally honest with yourself about how you can change your body, or if you even want to, or need to. Consider how it can help you reach your goals. For instance, are your nagging injuries due to weak muscles, a lack of strength (i.e., lack of endurance), or some extra weight you're carrying around due to the pandemic or otherwise? The ESPN annual publication I mentioned above reminds us that mom and dad gave us our body types (tendons and ligaments included), we can only change them by so much (or so little). However, even though your upper and lower limits are set, that portion in between is large! Maximize it!
As it pertains to running mechanics, Epstein makes the case that ankle mass is the most important variable in determining stride rate (a.k.a., cadence/RPMs), which makes sense because rotating mass is often where cyclists try to reduce the weight (“cut the costs”), hence the invention of $500+ cycling shoes and wheels that weigh as much as a pen. So, if your ankles and calves are very skinny and your feet aren’t too big, then yes, it is (objectively speaking) much easier for you to run with a cadence of ~90+ RPMs, especially if your height is ~5’5” or shorter (women) or ~5’9” or shorter (men), which is the prototypical for the professionals. Therefore, are we seriously going to overlook that leg length and thigh thickness affect stride rate/cadence!? Of course they have an effect!!! The next time you read an article that begins, “according to a university lab study on stride rate,” please read it with a grain of salt and half an eye-roll, as these studies are usually methodologically flawed and/or lack proper control groups, and lack long-term follow-up data points.
When I first meet with runners/athletes who are 6’0” or taller (regardless of gender), I am never surprised when they tell me how awkward and unnatural it feels for them to strive for ~90 RPMs, and it’s not a mystery. It’s not them, it’s the misinformation on “proper run form” that they read somewhere (note: yes, I understand that my own article here is an article related to run form ;) So, in coming from a different persepctive, I’m able to offer them peace of mind in not focusing so much on stride rate, and the same holds true for the people I coach with “thick/thunder thighs” or really big calves, as it’s going to require more work/METs to churn the legs as fast as our Olympians, so why fight it? Can we be okay with a cadence that’s 80+ and therefore focus on more important elements of running performance, such as stride length?
Again, as biological creatures, this largely goes back to mom and dad. Body type also affects stride length capability (a.k.a., range of motion…the most important factor in run performance/ injury prevention), as well as arm swing, the latter of which applies to “bulkier/muscular” folks who were formerly team-sport (or ball-sport) athletes who picked up running post-college (for example). I’m able to grant them much peace of mind that their arm swing checks-out okay (in all 5 gears), whereas it was formerly potentionally misdiagnosed due to their bulkier shoulders/arms that don’t fit the “prototypical runner look”. I’ve been fortunate enough to have a few convos about running form with our USA Olympic Track & Field Coach, Andrew Valmon, as he is the head T&F coach for Univ of Maryland, where I am finishing my PhD in performance psychology (emphasis on pain psychology and personality). We both acknowledge that it’s tough to put a “one size fits all” approach on run mechanics.
Footstrike is the another category where body type can play a role, and I can address this separately another time, as “forefoot” runners typically have the same exact injury history as one another in my many years of coaching experience (i.e., Achilles tendinitis, plantar fasciitis, and sharp knee pain) and the same very (very) small stride and relatively slow pace when I first meet them (prior to corrections being made), which is slower than a speed-walk. Related to the above point about ankle mass and cadence, if you can naturally run with a cadence ~90+ RPMs at 60+ miles per week, with zero injuries, then maybe you do land on your forefoot and run faster than a 10:00/mile (god bless you), but the overwhelming majority of evidence doesn’t support this notion, and it’s usually a midfoot strike (the semantics/language is so vital here! “We think in terms of language”), or a subtle heel strike that we see in elite runners/triathletes and most other pro athletes in all sports. Zoom in on that still frame (regardless of sport), the overwhelming majority of pro runners/athletes, despite their favorable body type, ain’t landin’ on the balls of their feet! Whew! That’s much peace of mind for many of you reading this article! The main take-away is that there is much more room for individual differences/freedom in run mechanics than what you previously might have heard. I’m available for Running 101 sessions, where the sole focus is YOU and YOUR run form, not a plastic mold that is forced over your body (or body type).
"Most people start running in order to get fit, whereas more people should first be getting fit in order to run" —Sonya, a wonderful PT/cyclist in DC. This quote reminds us to take your strength training (ST) and cross-training (XT) to heart this winter if you have ambitious running goals. You don't have to “look like a runner" to perform your best, but you can revisit your checklist of what it is that you can do to love yourself…your body...that thing that hosts your consciousness, and that’s what makes you human.
Train hard, and be good to yourself!